Modulated optical fiber laser sources have proven useful in applications ranging from fiber communications systems to
optical fiber sensors. As with many other coherent light sources, fiber lasers can easily be modulated by means of
electro-optical devices; several modulation schemes have been successfully reported. In this paper, we report on a fiber
laser with modulation regimes achieved by means of polarization feedback. The all-fiber laser cavity is based on a
Fabry-Perot arrangement in which single or dual polarization output can be obtained upon adjusting the intra-cavity
birefringence. Feedback of one polarization yields several effects on the population dynamics of the fiber laser, thereby
providing a simple way of achieving a dual polarization modulated output. Monitoring of both polarization modes
show that during modulation, polarization dynamics can exhibit in-phase and anti-phase behavior, and for pump power
levels well above threshold, chaotic-like behavior can also be observed. Experiments show that the modulated regime
obtained with the fiber laser depends on operating parameters such as pump power level, intra-cavity birefringence and
the phase of the polarized mode used as a feedback signal. As shown through radio-frequency spectral analysis, the
proposed arrangement could provide a simple polarimetric sensing scheme with radio-frequency readout for fiber optic
sensors. Finally, we discuss the use of the proposed fiber laser in applications such as polarization-switched sensing
and self-mixing interferometry.